Encoding

Data Structures
struct	RcOverride

Macros
#define	FF_MIN_BUFFER_SIZE   16384
	minimum encoding buffer size Used to avoid some checks during header writing.

Enumerations
enum	Motion_Est_ID {   ME_ZERO = 1, ME_FULL, ME_LOG, ME_PHODS,   ME_EPZS, ME_X1, ME_HEX, ME_UMH,   ME_TESA, ME_ITER =50 }
	motion estimation type. More...

Functions
AVCodec *	avcodec_find_encoder (enum AVCodecID id)
	Find a registered encoder with a matching codec ID.
AVCodec *	avcodec_find_encoder_by_name (const char *name)
	Find a registered encoder with the specified name.
int attribute_deprecated	avcodec_encode_audio (AVCodecContext *avctx, uint8_t *buf, int buf_size, const short *samples)
	Encode an audio frame from samples into buf.
int	avcodec_encode_audio2 (AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame, int *got_packet_ptr)
	Encode a frame of audio.
attribute_deprecated int	avcodec_encode_video (AVCodecContext *avctx, uint8_t *buf, int buf_size, const AVFrame *pict)
int	avcodec_encode_video2 (AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame, int *got_packet_ptr)
	Encode a frame of video.
int	avcodec_encode_subtitle (AVCodecContext *avctx, uint8_t *buf, int buf_size, const AVSubtitle *sub)

Detailed Description

Macro Definition Documentation

#define FF_MIN_BUFFER_SIZE   16384

minimum encoding buffer size Used to avoid some checks during header writing.

Definition at line 624 of file avcodec.h.

Referenced by avcodec_encode_video(), encode_frame(), encode_nals(), encode_picture_ls(), flashsv2_encode_frame(), gif_encode_frame(), ljpeg_encode_frame(), prores_encode_frame(), svq1_encode_frame(), and xvid_encode_frame().

Enumeration Type Documentation

enum Motion_Est_ID

motion estimation type.

Enumerator:

ME_ZERO	no search, that is use 0,0 vector whenever one is needed
ME_FULL
ME_LOG
ME_PHODS
ME_EPZS	enhanced predictive zonal search
ME_X1	reserved for experiments
ME_HEX	hexagon based search
ME_UMH	uneven multi-hexagon search
ME_TESA	transformed exhaustive search algorithm
ME_ITER	iterative search

Definition at line 631 of file avcodec.h.

Function Documentation

AVCodec* avcodec_find_encoder

(

enum AVCodecID

id

)

Find a registered encoder with a matching codec ID.

Parameters

id	AVCodecID of the requested encoder

Returns

An encoder if one was found, NULL otherwise.

Examples:

decoding_encoding.c, muxing.c, transcode_aac.c, and transcoding.c.

Definition at line 2807 of file utils.c.

Referenced by add_stream(), audio_encode_example(), avcodec_get_name(), avcodec_get_type(), avcodec_open2(), avcodec_string(), choose_encoder(), compute_status(), config(), config_props(), estimate_best_b_count(), ffserver_opt_preset(), filter_codec_opts(), find_codec_or_die(), open_output_file(), read_ffserver_streams(), show_codecs(), transcode_init(), and video_encode_example().

AVCodec* avcodec_find_encoder_by_name

(

const char *

name

)

Find a registered encoder with the specified name.

Parameters

name	name of the requested encoder

Returns

An encoder if one was found, NULL otherwise.

Definition at line 2812 of file utils.c.

Referenced by find_codec_or_die(), opt_codec(), and show_help_codec().

int attribute_deprecated avcodec_encode_audio	(	AVCodecContext *	avctx,
		uint8_t *	buf,
		int	buf_size,
		const short *	samples
	)

Encode an audio frame from samples into buf.

Deprecated:

Use avcodec_encode_audio2 instead.

Note

The output buffer should be at least FF_MIN_BUFFER_SIZE bytes large. However, for codecs with avctx->frame_size equal to 0 (e.g. PCM) the user will know how much space is needed because it depends on the value passed in buf_size as described below. In that case a lower value can be used.

Parameters

	avctx	the codec context
[out]	buf	the output buffer
[in]	buf_size	the output buffer size
[in]	samples	the input buffer containing the samples The number of samples read from this buffer is frame_size*channels, both of which are defined in avctx. For codecs which have avctx->frame_size equal to 0 (e.g. PCM) the number of samples read from samples is equal to: buf_size * 8 / (avctx->channels * av_get_bits_per_sample(avctx->codec_id)) This also implies that av_get_bits_per_sample() must not return 0 for these codecs.

Returns

On error a negative value is returned, on success zero or the number of bytes used to encode the data read from the input buffer.

Definition at line 1885 of file utils.c.

int avcodec_encode_audio2	(	AVCodecContext *	avctx,
		AVPacket *	avpkt,
		const AVFrame *	frame,
		int *	got_packet_ptr
	)

Encode a frame of audio.

Takes input samples from frame and writes the next output packet, if available, to avpkt. The output packet does not necessarily contain data for the most recent frame, as encoders can delay, split, and combine input frames internally as needed.

Parameters

avctx

codec context

avpkt

output AVPacket. The user can supply an output buffer by setting avpkt->data and avpkt->size prior to calling the function, but if the size of the user-provided data is not large enough, encoding will fail. If avpkt->data and avpkt->size are set, avpkt->destruct must also be set. All other AVPacket fields will be reset by the encoder using av_init_packet(). If avpkt->data is NULL, the encoder will allocate it. The encoder will set avpkt->size to the size of the output packet.

If this function fails or produces no output, avpkt will be freed using av_free_packet() (i.e. avpkt->destruct will be called to free the user supplied buffer).

Parameters

[in]	frame	AVFrame containing the raw audio data to be encoded. May be NULL when flushing an encoder that has the CODEC_CAP_DELAY capability set. If CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame can have any number of samples. If it is not set, frame->nb_samples must be equal to avctx->frame_size for all frames except the last. The final frame may be smaller than avctx->frame_size.
[out]	got_packet_ptr	This field is set to 1 by libavcodec if the output packet is non-empty, and to 0 if it is empty. If the function returns an error, the packet can be assumed to be invalid, and the value of got_packet_ptr is undefined and should not be used.

Returns

0 on success, negative error code on failure

Examples:

decoding_encoding.c, muxing.c, transcode_aac.c, and transcoding.c.

Definition at line 1751 of file utils.c.

Referenced by audio_encode_example(), avcodec_encode_audio(), do_audio_out(), encode_audio_frame(), encode_write_frame(), flush_encoders(), wrap(), and write_audio_frame().

attribute_deprecated int avcodec_encode_video	(	AVCodecContext *	avctx,
		uint8_t *	buf,
		int	buf_size,
		const AVFrame *	pict
	)

Deprecated:

use avcodec_encode_video2() instead.

Encode a video frame from pict into buf. The input picture should be stored using a specific format, namely avctx.pix_fmt.

Parameters

	avctx	the codec context
[out]	buf	the output buffer for the bitstream of encoded frame
[in]	buf_size	the size of the output buffer in bytes
[in]	pict	the input picture to encode

Returns

On error a negative value is returned, on success zero or the number of bytes used from the output buffer.

Definition at line 1969 of file utils.c.

Referenced by filter(), and wrap().

int avcodec_encode_video2	(	AVCodecContext *	avctx,
		AVPacket *	avpkt,
		const AVFrame *	frame,
		int *	got_packet_ptr
	)

Encode a frame of video.

Takes input raw video data from frame and writes the next output packet, if available, to avpkt. The output packet does not necessarily contain data for the most recent frame, as encoders can delay and reorder input frames internally as needed.

Parameters

avctx

codec context

avpkt

output AVPacket. The user can supply an output buffer by setting avpkt->data and avpkt->size prior to calling the function, but if the size of the user-provided data is not large enough, encoding will fail. All other AVPacket fields will be reset by the encoder using av_init_packet(). If avpkt->data is NULL, the encoder will allocate it. The encoder will set avpkt->size to the size of the output packet. The returned data (if any) belongs to the caller, he is responsible for freeing it.

If this function fails or produces no output, avpkt will be freed using av_free_packet() (i.e. avpkt->destruct will be called to free the user supplied buffer).

Parameters

[in]	frame	AVFrame containing the raw video data to be encoded. May be NULL when flushing an encoder that has the CODEC_CAP_DELAY capability set.
[out]	got_packet_ptr	This field is set to 1 by libavcodec if the output packet is non-empty, and to 0 if it is empty. If the function returns an error, the packet can be assumed to be invalid, and the value of got_packet_ptr is undefined and should not be used.

Returns

0 on success, negative error code on failure

Examples:

decoding_encoding.c, muxing.c, and transcoding.c.

Definition at line 2004 of file utils.c.

Referenced by avcodec_encode_video(), do_video_out(), encode_frame(), encode_write_frame(), filter_frame(), flush_encoders(), video_encode_example(), worker(), wrap(), and write_video_frame().

int avcodec_encode_subtitle	(	AVCodecContext *	avctx,
		uint8_t *	buf,
		int	buf_size,
		const AVSubtitle *	sub
	)

Definition at line 2085 of file utils.c.

Referenced by do_subtitle_out(), and wrap().